Drag = {
 obj : null,
 init : function(o,oRoot,minX,maxX,minY,maxY,bSwapHorzRef,bSwapVertRef,fXMapper,fYMapper){
  o.onmousedown	= Drag.start;
  o.onselectstart=function(){return false;}
  oRoot.onmousedown = function(){this.style.zIndex = max_zIndex();}
  o.hmode	= bSwapHorzRef ? false : true ;
  o.vmode	= bSwapVertRef ? false : true ;
  o.root = oRoot && oRoot != null ? oRoot : o ;
  if (o.hmode  && isNaN(parseInt(o.root.style.left  ))) o.root.style.left   = "200px";
  if (o.vmode  && isNaN(parseInt(o.root.style.top   ))) o.root.style.top    = "200px";
  if (!o.hmode && isNaN(parseInt(o.root.style.right ))) o.root.style.right  = "0px";
  if (!o.vmode && isNaN(parseInt(o.root.style.bottom))) o.root.style.bottom = "0px";
  o.minX = typeof minX != 'undefined' ? minX : null;
  o.minY = typeof minY != 'undefined' ? minY : null;
  o.maxX = typeof maxX != 'undefined' ? maxX : null;
  o.maxY = typeof maxY != 'undefined' ? maxY : null;
  o.xMapper = fXMapper ? fXMapper : null;
  o.yMapper = fYMapper ? fYMapper : null;
  o.root.onDragStart = new Function();
  o.root.onDragEnd = new Function();
  o.root.onDrag = new Function();
 },
 start : function(e){
  var o = Drag.obj = this;
  e = Drag.fixE(e);
  var y = parseInt(o.vmode ? o.root.style.top  : o.root.style.bottom);
  var x = parseInt(o.hmode ? o.root.style.left : o.root.style.right );
  o.root.onDragStart(x,y);
  o.lastMouseX = e.clientX;
  o.lastMouseY = e.clientY;
  if(o.hmode){
  if(o.minX != null)	o.minMouseX	= e.clientX - x + o.minX;
  if(o.maxX != null)	o.maxMouseX	= o.minMouseX + o.maxX - o.minX;
  }else{
  if(o.minX != null) o.maxMouseX = -o.minX + e.clientX + x;
  if(o.maxX != null) o.minMouseX = -o.maxX + e.clientX + x;
  }
  if(o.vmode){
   if(o.minY != null)	o.minMouseY	= e.clientY - y + o.minY;
   if(o.maxY != null)	o.maxMouseY	= o.minMouseY + o.maxY - o.minY;
  }else{
   if(o.minY != null) o.maxMouseY = -o.minY + e.clientY + y;
   if(o.maxY != null) o.minMouseY = -o.maxY + e.clientY + y;
  }
  document.onmousemove = Drag.drag;
  document.onmouseup = Drag.end;
  return false;
 },
 drag : function(e){
  e = Drag.fixE(e);
  var o = Drag.obj;
  var ey	= e.clientY;
  var ex	= e.clientX;
  var el = 0;
  var er = document.body.clientWidth-Drag.obj.root.offsetWidth;
  var eb = document.body.clientHeight-Drag.obj.root.offsetHeight;
  if(Drag.obj.root.offsetTop<el){Drag.obj.root.style.top = el;return;}//上
  //if(Drag.obj.root.offsetTop>eb){Drag.obj.root.style.top = eb;return;}//下
  if(Drag.obj.root.offsetLeft<el){Drag.obj.root.style.left = el;return;}//左
  if(Drag.obj.root.offsetLeft>er){Drag.obj.root.style.left = er;return;}//右
  var y = parseInt(o.vmode ? o.root.style.top : o.root.style.bottom);
  var x = parseInt(o.hmode ? o.root.style.left : o.root.style.right);
  var nx,ny;
  if (o.minX != null) ex = o.hmode ? Math.max(ex, o.minMouseX) : Math.min(ex,o.maxMouseX);
  if (o.maxX != null) ex = o.hmode ? Math.min(ex, o.maxMouseX) : Math.max(ex,o.minMouseX);
  if (o.minY != null) ey = o.vmode ? Math.max(ey, o.minMouseY) : Math.min(ey,o.maxMouseY);
  if (o.maxY != null) ey = o.vmode ? Math.min(ey, o.maxMouseY) : Math.max(ey,o.minMouseY);
  nx = x + ((ex - o.lastMouseX) * (o.hmode ? 1 : -1));
  ny = y + ((ey - o.lastMouseY) * (o.vmode ? 1 : -1));
  if (o.xMapper)nx = o.xMapper(y);
  else if (o.yMapper)ny = o.yMapper(x);
  Drag.obj.root.style[o.hmode ? "left" : "right"] = nx + "px";
  Drag.obj.root.style[o.vmode ? "top" : "bottom"] = ny + "px";
  Drag.obj.lastMouseX	= ex;
  Drag.obj.lastMouseY	= ey;
  Drag.obj.root.onDrag(nx,ny);
  return false;
 },
 end : function(){
  document.onmousemove = mousemove;
  document.onmouseout = mouseout;
 },
 fixE : function(e){
  if (typeof e == 'undefined') e = window.event;
  if (typeof e.layerX == 'undefined') e.layerX = e.offsetX;
  if (typeof e.layerY == 'undefined') e.layerY = e.offsetY;
  return e;
 }
};

function mousemove(){}
function mouseout(){}